package cn.tedu.sp06.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component
public class OrderFB implements FallbackProvider {

    // 针对哪个服务应用当前降级类，返回服务id
    // item-service 只针对商品服务降级.*通配符,针对所有
    @Override
    public String getRoute() {
        return "order-service";
    }

    // 返回的降级响应，封装在response对象中
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {

        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;    // 500
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {

                // BAIS 流是内存数组的流，不占用底层系统资源

            }

            @Override
            public InputStream getBody() throws IOException {

                String json = JsonResult.err().code(500).msg("系统服务故障").toString();

                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {

                HttpHeaders h = new HttpHeaders();
                h.add("Content-type", "application/json;charset=utf-8");

                return h;
            }
        };
    }

}
